Hydraulic-valve mechanism.



I w. F. COLE. HYDRAULIC VALVE MECHANISM.

(Application filed Mm. 1, 1898.)

No. 700,740. 7 Patent ed May 27, I902.

(No Model.)

3 Sheets-Sheet l.

7 III/IIII/IIIIIII iii "1771771577 711 No. 700,740. Patented may 27, I902.

w. F. COLE.

HYDRAULIC VALVE MECHANISM.

(Application filed Mar} 1, 1898.) I (No Modal.) 3 Sheets-Sheet 2.

z 6 4- eff THE norms rzrzps ca, PNDTO-L'iTNQ, WASHINGTON, a. c,

No. 700,740. 7 Patented May 27, I902.

W. COLE.

HYDB'AU UG. VALVE MECHANISM. (A ueati filqd Mai: 1. 1398. (No Modem 3 Sheets-Sheet 3.

In Jew/140K. wulwm T C'ole in: Noam; PUERS co. wcmilma. w-suma ou, a c.

UNITED STATES PATENT OFFICE.

IVILLIAM F. COLE, OF WVORCESTER, MASSACHUSETTS, ASSIGNOR TO PLUN- GER ELEVATOR COMPANY, OF WORCESTER, MASSACHUSETTS.

HYDRAULIC-VALVE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 700,740, dated May 27, 1902. Application filed March 1, 1898. Serial No. 672,167. N 11105 10 To all whmn it may concern:

Be it known that 1, WILLIAM F. COLE, a citizen of the United-States of America,jand a resident of Vforcester, county of Worcester, State of Massachusetts, have invented certain new and useful Improvements in Hydraulic- Valve Mechanism, of which the following is a specification.

My invention relates to regulating mechanism for elevators, whereby the elevator-car maybe started and reach full speed as quickly as desired; but however suddenly the operative may attempt to stop the car the suddenness of stopping is regulated within a predetermined limit, thus permitting a quick start and insuring a slow stop.

In the particular form set forth in this specification my invention concerns the valve mechanism for controlling the supply and discharge of fluid under pressure to the motor operated by said fluid. In hydraulic eleva tors such valves are commonly used to con trol the supply of water under pressure to the elevator-cylinder, and in the modern highspeed elevator the particular form known as the pilot-valve is used. This comprises, essentially, in addition to the main valve itself a motor-cylinder, within which works a piston suitably connected with the main-valve stem for the purpose of shifting the same, a secondary or pilot valve for controlling the flow of motive fluid to and from this motorcylinder, and of suitable connections between the main-valve stem and the secondary valve and the operating-handle. The secondary or pilot valve is opened by means of the op-' crating-handle and is closed by the movement of the main-valve stem transmitted by means of the connections to the secondary-valve stem, which is thereby moved to its closed position without affecting the-position of the operating-handle.

- In modern high-speed elevators it is desirable to have the car reach its maximum rate of speed as soon as possible after starting; but any sudden stopping of the car is undesirable. Among other objections sudden stopping is the cause of an extremely unpleasant sensation which the passengers are made to feel, and in the case of the plunger type of hydraulic elevator if the supply of water to the cylinder be shut 0E too suddenly the momentum of the rapidly-movin g parts which comprise a considerable mass is so great that the plunger will be apt to jump off the water, causing an extremely disagreeable shock to be felt by the passengers. Moreover, sudden stoppage of so great a mass of rapidly-movingmatter which has attained considerable momentum puts a sudden strain on the machinery. It becomes, therefore, a matter of great importance to stop the car gradually, requiring the exercise of considerable care on the part of the elevator operative. Obviously it is not desirable to leave the possibility of sudden stopping in the hands of the operative. This has already been recognized, and a gradual stoppage has been accomplished in several ways by means entirely independent of the controlling device in the car. One method has been to make the ports of the secondary or pilot valve quite small or to throttle them down by means of a screw-plug, which is left permanently adjusted in the required position, allowing only a comparatively small volume of water to ,flow to or from the motor-cylinderin a given time. A similar result is sometimes accomplished by constructingthe portsof the main valve of such shape that .as the valve closes the wateris gradually shutoff. These ,per-

manent adj ustmentswhich accomplisha gradual stop, both going up and coming down, also of necessity accomplish a gradual start in either direction. To gradually overcome the energy of such a large mass of rapidlymoving matter as is required in an elevator .without the undesirable effects above referred to, it is necessary to begin to slow down several feet before the floor at which it is desired to stop is reached. To accomplish this, the movement of the main valve in closing must be very gradual. When the elevator is started, however, it is not necessary nor desirable that full speed should be as gradually reached from full stop as was full stop when the elevator was running at fulLspeed. In fact, full speed can be safely acquired in several feet less travel than within which it would be desirable to stop a car from full speed. Therefore it is not necessary that the main valveshould move as gradually in open-- ing or that the same means, if any, should be employed for a gradual start as must of necessity exist in the means for gradual stoppage, which I have referred toabove.

My invention has forits chief object to provide mechanism whereby an elevator-car may be started and permitted to reach full speed as quickly as desired; but however suddenly the operative may attempt to stop the car the suddenness of stopping shall be limited to a predetermined limit.

Myinvention consists, essentially, of means adapted to regulate at independent rates the sudden'ness of starting and stopping an elevator-car.

More particularly my invention consists of means attached to the valve mechanism which limits the rate of speed of closing the main valve in either direction without affecting its rate of speed of opening.

In the accompanying drawings, Figure 1 is an elevation of the main valve, showing situation of the secondary or pilot valve and the throttling-valve, the latter in cross-section. Fig. 2 is a view, partly in section and partly in elevation, of the main valve, the motor-cylinder, the pilot-valve, and their connections. Figs. 3 and 4 are cross-sectional views showing the main valve and motor-cylinder with the pilot and throttling valves enlarged and arranged to show clearly their operation. Fig. 4 shows the samevalve represented by Fig. 3, but in a ditferent position. Fig. 5 shows a modification of the throttling-valve. Fig. 6 is a diagrammatic view showing the valve V, plunger 20, controlling-rope z, and car y.

Referring to Figs. 1 and 2, A denotes the main-valve cylinder; 13, the motor-cylinder, placed parallel with and at one side of the main-valve cylinder and containing the motorpistonsband I), mounted upon the piston-rod C, which is connected by means of a link 0 to the lever-beam D, journaled at its other end in the arm I. The main-valve stem F, upon which are mounted the main-valve pistons a a a a is connected to the lever-beam by linkf. The valve-pistons are arranged to balance the valve as regards pressure and to divide the supply-chamber d from the port-chamber g and said port-chamber from the exhaustchamber h.

The main-valve stem is moved upward or downward by means of its connection to the lever-beam as the "lever-beam is moved upward or downward by means of its connection to the motor-piston rod C. Thus from an intermediate position, as shown, in which there is no communication from the supply through the port-chamber to the elevator-cylinder or from the elevator-cylinder through the portchamber to the exhaust, the main-valve stem is moved in either direction to establish such communication. The actuating member for moving the main valve comprises the motorpistons, which are moved in either direction by pressure from the supply admitted through passages (not shown in Figs. 1 or 2) and controlled by the pilot-valve P, which is operated from the elevator-car by means of a controlling device (not shownlconnected to the operating-handle J. The pilot-valve stem is connected by means of the links Z m to the handle J and the lever-beam D. I

The throttling-valve T is shown in crosssection in Fig. 1 applied to the supply and dischargs ports 8 and t of the pilot-valve and is operated by means of its connections 0 p with the lever-beam as the main valve moves. The passages to the motor-cylinder are shown in Figs. 3 and 4:, and in the description which follows the details of construction and mode of operation of the throttling and pilot valves will be described more particularly.

- In Figs. 3 and 4, which represent the mechanism in differentpositions, the pilot and throttling valves have been represented one above the other to show more clearly their construction and operation.

The main-valve cylinder 1 is provided with I supply, port, and exhaust chambers 2, 3, and 4, respectively, the openings of which to the supply, elevator-cylinder, and exhaust are denoted by S, E, and X, respectively.

As the main-valve stem 5, with the pistons 2 3 4, is moved from its intermediate position, (shown in Fig. 3,) in which no water can flow to or from the elevator-cylinder, to the position shown in Fig. 4 communication is established between the supply and port chambers and the water is allowed to flow into the elevator-cylinder.

The main-valve stem 5 is attached by the link 6 to the lever-beam 7. This lever-beam is pivoted at one end at Sto the rigid arm 9, attached to the main-valve cylinder. The other end 10 of this lever-beam is connected, by means of a link 11, to the piston-rod 12 of the valve-actuating member or valve-motor. This valve-motor comprises the cylinders 15 and 15, in which are fitted the pistons 14 and 13, respectively mounted on the piston-rod 12. The cylinder 15,with its piston 14,is about twice the sectional area of the cylinder 15 with its piston 13, and these cylinders are placed together or constructed to form the continuous motor-cylinder of two diameters.

Water-pressure is admitted from the supply betwcen the two pistons at a point 16. This passage to the supply is indicated by the pipe 17, connected to the supply S. At the other end of the enlarged portion 15 of the cylinder water under the supply-pressure is admitted at 19 from the pipe 18. The fiow of water through this pipe is controlled by the pilot-valve, as will be presently described.

As the pipe 17 is always open, the pressure from the supply is always acting between the pistons 13 and 14; but as the piston 14 is the larger of the two the unbalanced pressure on these differential pistons shifts them to the left from the intermediate position, (shown in Fig. 3,) and the lever-beam is drawn in the same direction, opening the main valve from the port-chamber to the exhaust-chamber.

This of course occurs only when the port 19 and pipe 18 are open to exhaust. When the pilot-valve is moved to admit water under supply-pressure at 19, the pressure admitted through the pipe 17 is balanced as regards the piston 14, but not as regards the piston 13. The unbalanced pressure now, therefore, moves the pistons to the right, as shown in Fig. 4, and the main valve is moved to admit waterfrom the supply-chamber to the portchamber.

In the pilot-valve cylinder 20 are fitted the pistons 21, 22, and 23, mounted upon the valve-stem 24. The supply is admitted by the passage to the supply,chamber 26,which is normallyclosed or cut off from the supplydischarge chamber 27 by the piston 21. The supply-discharge chamber communicates, by means of the passage 28, with the pipe 18. This passage 28 also opens into the exhaustchamber 29 on the other end of the pilot-valve. This exhaust-chamberis normally closed from the exhaust-discharge chamber 30 by the piston 23. The piston 22 balances the valve and separates the supply-discharge chamber from the exhaust-discharge chamber.

The pilot-valve stem 24 is connected to the operating-handle 33 bythe links 31 and 32, pivotally connected .to each other at their ends 34 and at their other ends to the pilotvalve stem and operating-handle, respectively. A link 35 is also pivotally connected to the lever-beam 7 and to the pivotal connection at 34. These links are arranged to accomplish the opening of the valve when the operating-handle is moved and its automatic closing when the lever-beam moves. When the operating-handle is depressed, as in Fig. 4, the links 31, 32, and 35 occupy the positions shown in dotted lines and the pilot-valve is thrown open to the supply, as shown in dotted lines. Water-pressure is thereupon admitted through the pipe 18 to cylinder 15 and the motor-pistons are moved to the right, thus shifting the main valve to a position as shown in Fig. 4. Upon this movement of the lever-beam the links 31, 32, and 35, owing to their connection by the link 35 to the leverbeam, are moved from position shown in dotted lines, in which the pilot-valve is open, to the position shown in full lines, in which the pilot-valve is closed, thus arresting automatically any further action of the motor-pistons.

When the operating-handle is raised, the pilot valve is opened to exhaust from the motor-cylinder and the main valve moves to the left until the pilotvalve is automatically closed by the movement of the lever-beam and the links. Thus for every position of the operating-handle there exists a corresponding position toiwhich the main-valve stem will be. driven and there brought to rest.

As before referred to, it has been necessary to contract the ports of the pilot-valve to such a size that the flow of water to the motor-cylinder will be reduced, which will cause the main valve to be moved to its closed position gradually, so that the stoppage of the eleva tor will be gradual; but it is evident that such permanently-contracted ports will also cause a gradual start and occasion unnecessary delay in getting up speed. The throttling-valve 40, which I am about to describe, overcomes this difficulty, and by its useI am enabled to secure a quick start and a slow stop. The throttling-valve cylinder is provided with the supply-chamber 41 in communication with the supply-port 25 of the pilotvalve and with the exhaust-chamber 42 in communication with the exhaust-port 25, leading from the exhaust-discharge chamber 30 of the pilot-valve. From the supplychamber 41 two'passages 43 and 44 communicate with the supply-pipe 45. From the exhaust-chamber 42 two passages 47 and 48 communicate with the exhaust-pipe 49. The passages 43 and 47 are of such a size that the water will flow through them to and from the motor-cylinder by way of the pilot-valve in sufifiicient volume to move the motor-cylinder at that rate of speed at which it is desired to I open the main valve to start the elevator in either direction.

The passages or by-passes 44 and 48 are comparatively smaller than the passages 43 and 47, and may be further contracted by adjustable' plugs 50 and 51 to such a size to allow the water to flow in such volume to and from the motor-cylinder that the main valve will be closed at the desired rate of speed necessary to accomplish a slow stop. The usual screw-plugs heretofore provided on the supply and exhaust 45 49 and used to effect a gradual stoppage and of necessity effecting a gradual start, as referred to above, or the size of the passages 43 and 47 which are permanently fixed, would limit the maximum rate of speed at which the main valve maybe opened, while the rate of closing is limited by the adjustable by -passes. These contracted passages are always open to their respective ports of the pilot-valve, but the enlarged passages, although both are open when the main valve is in its intermediate position, are alternately closed to compel the water to flow through that contracted passage through which it is necessary to admit or exhaust water to bring the main valve from its open to its closed position. To accomplish this, the pistons 52and 53 are mounted upon piston-rod 55 and adapted to alternately close the passages 43 and 47, respectively. Piston 54 divides the two enlarged passages. To a stationary part of the valve is attached abracket 56, to which is journaled at 57 a cam 58, in the lower end of which is formed aslot engaging the pin 59 on the piston-rod or valve-stem 55. As this cam is swung on its journal 57 the throttling valve stem is moved back and forth. To throw this'valve-stem immediately to its proper position in either direction upon a slight movement of the main valve from its intermediate position in either direction,there to remain during any further movement in IIO from its perpendicular position in either direction will throw the valve to its position, there to remain during any further movement of thelink in the same direction. This link 60 is also journaled to a link 64,which at its other 7 end is pivoted to some reciprocating part of the valve mechanism, as at 65, to the leverbeam 7. From this construction it will be'seen that as the main valve moves in either direction from its intermediate position (shown in Fig. 3) the throttling-valve is automatically moved to close one of the enlarged passages, leaving that corresponding contracted passage open, through which water must flow to or from the pilot-valve when the pilot-valve is opened to cause the main valve to be driven again to its intermediate position. For example, when the operatinghandle is moved from the position shown in Fig. 3, in which the pilot-valve is closed, to the position shown in dotted lines in Fig. 4 the pilot-valve is opened to admit the supply to the motor-cylinder. This supply entering at 45 finds a free passage through the enlarged passage 43 to the pilot-valve and from thence to the motor-cylinder, to which it flows in full volume, and the main valve is rapidly moved to the position shown in Fig.

4, and a quick start is accomplished through this movement of the main valve, which is driven to a position corresponding to the distance the operating-handle is moved. Link is moved sufficiently to cause the throttling-valve to be thrown from the position shown in Fig. 3 to that shown in Fig. 4. This closes the enlarged passage 47in the throttling-valve, leaving open to the exhaust from the motor-cylinder to the pilot-valve only the contracted passage 48, as shown in Fig. 4.

To bring the elevator to a stop, the operating-handle'is moved back to the position shown in Fig. 3. The pilot-valve is thereby opened to permit the water to exhaust from the motor cylinder, which it can do only through the contracted passage 48 at such a rate of speed as will allow the main valve to close gradually and to bring the elevator slowly to rest. hen the main valve has reached the intermediate position, the throttling-valve is automatically thrown to open both of its enlarged passages, through either of which water must be admitted for a start. In like manner upon the opposite end of the pilot and throttling valves the throttlingvalve closes the enlarged passage 43 when the main valve is moved to the left, and when it is moved from this position to its intermediate position it will move only as fast as the Water can flow through the contracted passage 44 to fill the motor-cylinder 15. Thus it will be seen that upon the upward and downward start the mechanism is in the intermediate position shown in Fig. 3 and the valve will move comparatively quickly; but upon the upward and downward stop the pilotvalve is throttled, andthe main valve will move correspondingly slowly. Thus it will be seen that in the regulating'means which I have here described as throttling-valve mechanism I provide means for ofiering resistance to the force applied to move the main valve by closing the enlarged free passage, thus requiring the fluid to flow through the contracted passage. As it is necessary upon each opening and closing movement of the main valve in either direction that water should flow through a separate passage,the regulating means is adapted to control the speed of any movement independently of the speed of any other movement.

WVhile I have described the throttling-valve as acting both upon the supply and exhaust ports of the pilot-valve, it is evident that a single-acting throttling-valve may be applied to one of the ports in order to accomplish a quick start in one direction only, and although I have shown the double-acting throttling-valve as located on the supply to and exhaust from the pilot-valveit will be evident they could also be placed between the pilot-valve and motor-cylinder or upon the ports of the main valve itself.

One modification I have shown in Fig. 5, which shows two valves Z and m applied, respectively, to the supply and exhaust 0 and n of the pilot-valve P. In this case both valves are open in the intermediate position shown, but are alternately closed as the rod q is moved back and forth.

As the valve mechanism of an elevator often has to be situated in very contracted space, it is highly desirable that it should be made as compact as possible. To accomplish this and other objects, I have arranged the motorcylinder parallel with and at one side of the main valve and connected the piston-rod of the cylinder bymeans of the link 11 to the lever-beam 7. Thus I avoid lengthening the main-valve cylinder to accommodate the motor-cylinder, making the entire mechanism more compact. I am also enabled by this means to reduce the size of the motor-cylinder, as I make use of the leverage obtained by connection to the lever-beam 7 Moreover, it will be seen that the motor-pistons move a greater distance in their travel than the main valve in its corresponding travel, and this enables the operative to be less exact in manipulating the controlling device in the car in making a stop.

My invention of throttling device is not limited to the form of throttling-valve shown,

What I claim as my invention, and desire to protect by Letters Patent, is

1. In an-elevator, the combination with the car, of motor means for running said car, controlling means adapted to be operated from the car, and an automatic quick-starting, slow-stopping device. adapted to permit of a quick start and to regulate the suddenness of stopping whereby the car will be brought to rest gradually.

2. The combination with the main three-way valve, of means for opening and closing said valve in either direction, and automatic means for regulatingthe opening and closing movements at different rates of speed.

3. The combination with the main valve for controlling the passage of fluid under pressure, of means for opening and closing said valve, and automatically-operated quickopening, slow-closing means connected with said main valve, whereby the speed of opening and the speed of closing the main valve are regulated within independent limits, substantially as described.

4. In a hydraulic elevator, the combination with a main valve, of a valve-motor, pilotvalve mechanism, and an opening and closing regulating means operated by movement of the main valve, whereby a quick opening and slow closing of the main valve are efiected.

5. The combination with the main valve for controlling the passage of fluid under pressure, of motor means for opening and closing said main valve, secondary valve mechanism for controlling the motor means, and hydraulic opening and closing regulating means for automatically regulating the velocity at which the main valve maybe opened and the velocity at which the main valve may be closed at independent rates, substantially as described. 7

6. In a hydraulic elevator, the combination with a main three-way valve which is adapted to be closed when in its middle position, of means for opening and closing said valve, and regulating means operated automatically by said main. valve and adapted to accomplish a quick opening and slow closing of said valve.

7. The combination with a main valve for controlling the passage of fluid under pres sure, of means for operating said valve, and means for regulating the speed of opening and the speed of closing. the main valve at independent rates, comprising enlarged and contracted water passages and automatic means for controlling the flow of fluid through said passages,-substantially as described.

8. The combination with the main valve for controlling the passage of fluid under pressure, of means for opening and closing said valve, speed-regulating means comprising separate passages for the flow of fluid in the operations of opening and closing the main valve in either direction, and automatic means adapted to regulate the flow of fluid through said passages, whereby the suddenness of opening and closing the main valve in either direction-can be regulated within independent limits.

9. The combination with the three -way valve which is adapted to be closed when in its middle position, of means for opening and 'regulator comprising fluid-passages through which fluid must flow when the main valve is moved, and automatic means for controlling the flow of fluid through said passages, whereby the velocity of opening and the velocity of closing of the main valve in either direction may be regulated at independent rates of speed.

10. In a device for controlling the rates of speed in opening and closing a three-way valve in either direction, the combination with a cylinder, havingin connection therewith, a contracted passage and an enlarged passage, of automatically-operated valve mechanism adapted to close said enlarged passage to the flow of fluid upon one movement of the main valve and open said enlarged passage tothe flow of fluid upon the other movement,whereby upon one movement the flow of fluid has a free passage and upon the other movement a restricted passage, substantially as described.

ll. The device for controlling the speed of opening and closing a valve, comprising a cylinder having in connection therewith enlarged passages, means for alternately closing said passages to the flow of fluid upon the dilferent movements of the main valve, and contracted passages through which the fluid may flow when the enlarged passages are closed, substantially as described.

12. The combination with a main three-way valve for controlling the supply and discharge of fluid under pressure, of means for opening automatic regulating means for ,ofiering to the force applied to move said valve, resistance, diflerent as between different movescribed.

13. The combination with a main three-way valve for controlling the passage of fluid under pressure, of means for opening and closing said valve in either direction, and auto matic means for oflfering to the force applied to open and close the main valve a resistance, different as between the opening and closing movementsof said valve, substantially as described.

- 14. The combination with an elevator-valve which is adapted to be closed when in an intermediate position and opened when moved in either direction from said position, avalve actuating member connected to said valve for moving same, means for permitting comparatively free movements of said actuating member in either direction from an intermeand closing said valve in either direction, and

ments of the main valve, substantially as dey diate position, and for correspondingly reclosingsaid valve, of an opening and closing.

IIO

stricting the speed at which said actuating member may be returned from its extreme position.

actuating member connected to said valve" for moving the same, means for permitting comparatively free movements of said actuating member in either direction from an intermediate position, and for correspondingly restricting the speed at which said actuating member may be returned from either extreme position.

16. The combination with the main threeway valve for controlling the passage of fluid under pressure, of an automatic opening and closing regulating mechanism applied to the main valve independent of the operating-handle and operating means connected with the main valve independent of the operatinghandle and operated by the movement of the main valve whereby the valve is closed in either direction more gradually than it is opened, substantially as described.

17. The combination with a three-way valve, of fluid-pressure operated motive means for moving said valve, means for controlling said fluid-pressure comprising a throttling-valve, meansfor automatically operating said throttling-valve which are connected to said main valve and are adapted to move said throttlingvalve so that said main valve is moved faster from a closed to an open position than from an open to a closed position.

18. The combination with a three-way valve, of motive means for moving said valve, means for controlling said motive means, and automatic regulating means comprising enlarged and contracted passages and valve mechanism for said passages, whereby the velocity of movements of the main valve may be regulated at diiferent rates, substantially as described.

19. The combination with a main valve, of a valve-motor for moving said valve, a pilotvalve for controlling the action of the valvemotor, a throttling-valve adapted to regulate the flow of fluid to and from the valve-motor at difierent rates of speed, and automatic operating mechanism for said throttling-valve, substantially as described.

20. The combination with a main hydraulic valve, of a valve-motor adapted to move the main valve, the secondary or pilot valve for controlling the direction of the flow of fluid to the valve-motor, and the throttling-valve applied to the ports of the pilot-valve and adapted to regulate the flow of fluid to and from the valve-motor, and connecting mechanism to the main valve-motor, whereby the main valve may be opened more rapidly than it is closed, substantially as described.

21. The combination with a main valve, of a valve-motor for moving said valve, a throttling-valveon the supply-passage to the motor, and a throttling-valve on the dischargepassage from the motor, of connections between said throttling-valves, whereby when either passage is th-rottled the other passage is open, and connections to-a reciprocating ated, substantially as described.

22. In a device for controlling the speed of opening and closing a valve, the combination with a valve-cylinder provided with an enlarged supply-passage and an enlarged exhaust-passage,of valve-pistons to control said passages, connections between said pistons whereby the passages are alternately opened and closed, contracted passages which are open when said enlarged passages are closed, and means for operating said pistons, substantially as described.

23. The combination with the main hydraulic. valve, of a valve-motor for opening and closing said valve, a pilot-valve for controlling the flow of motive fluid to the valve-motor, and a throttling-valve connected with the ports of the pilot-valve to regulate the flow of motive fluid to and from the valve-motor, and adapted to be automatically operated by the movement of the main valve to throttle that port of the pilot-valve through which fluid must flow to cansethe motor to close the main valve and at the same time to open that port of the pilot-valve through which fluid would flow to cause the valve-motor to open the main valve, substantially as described.

24. The combination with a main valve, of

a motor for moving said valve, a pilot-valve, and a throttling-valve having contracted passages continuously open to the supply and exhaust passages of the pilot-valve, and enlarged passages also open to said supply and exhaust, said enlarged passages adapted to be alternately closed by movements of the main valve, and valve-pistons and connections for closing said enlarged passages, substantially as described.

. 25. The combination with a main valve, of a val ve-motor and a pilot-valve, of a throttlingvalve applied to the supply and discharge ports of said pilot-valve and automatically operated by a connection to a reciprocating part of the; main valve, whereby the main valve is opened more rapidly than it is closed, substantially as described.

26. The combination with a main valve, of a valve-motor'for moving said valve, a pilotvalve for controlling the action of the valve motor, and a throttling device on the supply and exhaust of the pilot-valve comprising a valve-cylinder provided with an enlarged supply-passage and an enlarged exhaust-passage, of valve-pistons for closing said passages, connections between said pistons whereby said passages are alternately opened and closed, and contracted passages which are open when either of said enlarged passages IIO is closed, and connections to the main valve mechanism whereby the throttling device is automatically'operated, substantially as described. I

27. In an automatic throttling device, the

combination with a throttling-valve, of the reciprocating mechanism of the main valve, and setting means for the throttling-valve comprising connections to a reciprocating part of the mechanism moved by the valvemotor,wherebya slight movement of the main I valve near its middle position sets the throttling-valve, substantially as described.

28. In an automatic throttling device for a valve-motor, the combination with a valvemotor, of a throttling-valve, of a valve-stem, of a cam element engaging .said-valve-stem, and connections from a reciprocating part of the mechanism moved by the valve-motor to and means for guiding said r0d,'substantia1ly as described.

Signed by me at Worcester, Massachusetts, this 18th day of February, 1898.

WILLIAM F. COLE.

Witnesses:

JOHN :S. GOULD, ALDUS C. HIGGINS. 

